Heat sinks transfer heat from a hot area to a cooler area. Certain forms of heat sinks use fins or louvers but these heat sinks have difficulty supporting mechanical loads. In addition, odd shaped surfaces or even substantially non planar surfaces can be difficult to cool with heat sinks known in the art. Various heat sink designs include fins, pin fins, corrugated, and louvered fins. These designs may be incorporated in heat pipes and heat spreaders. These designs (with the exception of louvered fins) may have worse performance in terms of low heat transfer than truss designs. Furthermore, louvered fin designs cannot support loads, unlike truss designs, and are expensive to manufacture.
The use of a truss architecture for active cooling has been reported in literature (for instance, Lu, Valdevit, Evans, “Active cooling by metallic sandwich structures with periodic cores”, Progress in Materials Science 50 (2005) 789-815) However, the only fabrication methods described are expensive, limited to a single truss layer, and limited to large truss unit cell sizes.
Tian, Wadley, et al. (in “The effects of topology upon fluid-flow and heat-transfer within cellular copper structures”, International Journal of Heat and Mass Transfer volume 47, issues 14-16, July 2004, p. 3171-3186) have experimentally investigated copper ordered cellular materials as heat sinks. The structures described therein are constrained to simple, flat geometries, do not have enhancements for increased convective heat transport, and are not designed to support a load while transferring heat.
As such, there is a need for heat sinks that can support a mechanical load, that are economical to manufacture and that can conform to odd shapes.